Calycosin induces autophagy and apoptosis via Sestrin2/AMPK/mTOR in human papillary thyroid cancer cells

Neuropharmacological effects of calycosin: a translational review of molecular mechanisms and therapeutic applications

Calycosin, a naturally occurring isoflavonoid found predominantly in Astragalus membranaceus, exhibits significant therapeutic potential in various neurological conditions. Its multifaceted bioactive properties-antioxidant, anti-inflammatory, and anti-apoptotic-position it as a promising candidate for neuroprotection and neuroregeneration. This review explores calycosin's mechanisms of action, including its modulation of key signaling pathways such as HMGB1/TLR4/NF-κB (high mobility group box 1/toll-like receptor 4/nuclear factor kappa B), phosphatidylinositol-3-kinase (PI3 K)/Akt, ERK1/2 (extracellular signal-regulated kinase 1/2), and Hsp90/Akt/p38. In cerebral ischemia/reperfusion injury, calycosin reduces oxidative stress markers like ROS (reactive oxygen species) and MDA (malondialdehyde), enhances antioxidant enzymes (SOD (superoxide dismutase) and GPX (glutathione peroxidase)), and downregulates pro-inflammatory cytokines (TNF-α, IL-1β) through the HMGB1/TLR4/NF-κB pathway. It also inhibits autophagy via the STAT3/FOXO3a pathway and apoptosis by modulating Bax and Bcl-2 expression. In neuro-oncology, calycosin inhibits glioblastoma cell migration and invasion by modulating the TGF-β-mediated mesenchymal properties and suppressing the c-Met and CXCL10 signaling pathways. Additionally, it enhances the efficacy of temozolomide in glioma treatment through apoptotic pathways involving caspase-3 and caspase-9. Calycosin shows promise in Alzheimer's disease by reducing β-amyloid production and tau hyperphosphorylation via the GSK-3β pathway and improving mitochondrial function through the peroxisome proliferator-activated receptor gamma coactivator 1-Alpha (PGC-1α)/mitochondrial transcription factor A (TFAM) signaling pathway. In Parkinson's disease, calycosin mitigates oxidative stress, prevents dopaminergic neuronal death, and reduces neuroinflammation by inhibiting the TLR/NF-κB and MAPK pathways. It has also shown therapeutic potential in meningitis and even neuroprotective effects against hyperbilirubinemia-induced nerve injury. Despite these promising findings, further research, including detailed mechanistic studies and clinical trials, is needed to fully understand calycosin's therapeutic mechanisms and validate its potential in human subjects. Developing advanced delivery systems and exploring synergistic therapeutic strategies could further enhance its clinical application and effectiveness.

Flavonoids serve as a promising therapeutic agent for ischemic stroke

Ischemic stroke (IS) continues to be a major public health concern and is characterized by significantly high mortality and disabling rates. Inhibiting nerve cells death and enhancing the repair of ischemic tissue are important treatment concepts for IS. Currently, the mainstream treatment strategies mainly focus on short-term care, which underscores the urgent need for novel therapeutic strategies for long-term care. Emerging data reveal that flavonoids have surfaced as promising candidates for IS patients' long-term care. Flavonoids can alleviate neuroinflammation and anti-apoptosis due to their characteristic pharmacological mechanisms. Clinical evidence suggests that long-term flavonoids intake improves IS patients' long-term outcomes. Though the effect of flavonoids in IS treatment has been explored for decades, the neuroprotective pharmacodynamics have not been well established. Thereby, the aim of current review is to summarize the pathways involved in neuroprotective effect of flavonoids. This review will also advance the potential of flavonoids as a viable clinical candidate for the treatment of IS.

From Traditional Efficacy to Drug Design: A Review of Astragali Radix

Astragali Radix (AR), a traditional Chinese herbal medicine, is derived from the dried roots of Astragalus membranaceus (Fisch.) Bge. var. mongholicus (Bge.) Hsiao (A. membranaceus var. mongholicus, AMM) or Astragalus membranaceus (Fisch.) Bge (A. membranaceus, AM). According to traditional Chinese medicine (TCM) theory, AR is believed to tonify qi, elevate yang, consolidate the body's surface to reduce sweating, promote diuresis and reduce swelling, generate body fluids, and nourish the blood. It has been widely used to treat general weakness and chronic illnesses and to improve overall vitality. Extensive research has identified various medicinal properties of AR, including anti-tumor, antioxidant, cardiovascular-protective, immunomodulatory, anti-inflammatory, anti-diabetic, and neuroprotective effects. With advancements in technology, methods such as computer-aided drug design (CADD) and artificial intelligence (AI) are increasingly being applied to the development of TCM. This review summarizes the progress of research on AR over the past decades, providing a comprehensive overview of its traditional efficacy, botanical characteristics, drug design and distribution, chemical constituents, and phytochemistry. This review aims to enhance researchers' understanding of AR and its pharmaceutical potential, thereby facilitating further development and utilization.

Knockdown of SESN2 Exacerbates Cerebral Ischemia-Reperfusion Injury Through Enhancing Glycolysis via the mTOR/HIF-1α Pathway

AIM

Reprogramming of glycometabolism plays a crucial role in the pathogenesis of cerebral ischemia-reperfusion injury (CIRI). Sestrin2 (SESN2), a sensor upstream of the mTORC1, is closely related to glycometabolism. However, the effect and mechanism of SESN2 in CIRI are unclear. The goal of this research was to explore the effect of SESN2 on CIRI and its potential mechanisms related to glycometabolism.

METHODS

Lentiviral vectors carrying SESN2 shRNA (Lenti-SESN2) or negative NC virus (Lenti-GFP) or rapamycin (mTOR inhibitor) were employed in the oxygen-glucose deprivation/reoxygenation (OGD/R) model and in the middle cerebral artery occlusion (MCAO) mice. In all, 3 days after I/R, neurological deficit scores and infarct size were assessed. The glycolysis and SESN2 levels were determined by RT-qPCR, Western blots, and immunofluorescence staining. Lactate levels were detected by a lactate assay kit, and the expression of the p-mTOR/HIF-1α signaling pathway was measured by immunofluorescence staining and protein blotting.

RESULTS

Local SESN2 deficiency in brain tissue increased the infarct size and reduced neurological scores 3 days after I/R. Moreover, the results showed that local SESN2 deficiency in brain tissue increased the expression of glycolysis-related proteins, including HK2, PFKM, PKM1, PKM2, and GLUT1. The lactate assay kit showed that local SESN2 deficiency in brain tissue increased lactate levels. In addition, local SESN2 deficiency in brain tissue improved the expression of the p-mTOR/HIF-1α pathway. However, rapamycin (RAP) treatment reversed these results, suggesting that SESN2 may influence IS injury by regulating glycometabolism via p-mTOR/HIF-1α pathway regulation. SESN2 knockdown in BV2 cells improved the glycolysis levels and the expression of the mTOR/HIF-1α pathway in the OGD/R model in vitro, but RAP treatment can also reverse these results.

CONCLUSIONS

Knockdown of SESN2 in MCAO mice increased the expression of the p-mTOR/HIF-1α pathway, which increased glycolysis and lactate levels and, in turn, affected IS injury.

Relationship between programmed cell death and targeted therapy for thyroid cancer in patients with a poor prognosis: an update

In recent years, the incidence of thyroid cancer has steadily increased. However, the detailed mechanisms of pathogenesis are still unclear. Therefore, a comprehensive understanding of the underlying carcinogenesis mechanisms of thyroid cancer is required. Programmed cell death (PCD) is a cell death process mediated by specific molecular program, regulated by specific genes within the cell. Accumulating evidence suggests that PCD plays an indispensable role in thyroid cancer, maintaining intracellular stability by regulating genes and eliminating damaged or aged cells. In this review, we summarize six identified forms of PCD, analyze biomarkers for different PCD pathways in thyroid cancer, and briefly elucidate the roles of various PCD pathways in targeted therapies for thyroid cancers with a poor prognosis. We also provide an outlook on future treatments for drug-resistant thyroid cancer, poorly differentiated thyroid cancer, and iodine-refractory thyroid cancer, aiming to accurately identify targets and offer effective targeted therapeutic strategies.

Sestrin2 balances mitophagy and apoptosis through the PINK1-Parkin pathway to attenuate severe acute pancreatitis

Mitophagy serves as a mitochondrial quality control mechanism to maintain the homeostasis of mitochondria and the intracellular environment. Studies have shown that there is a close relationship between mitophagy and apoptosis. Sestrin2 (Sesn2) is a highly conserved class of stress-inducible proteins that play important roles in reducing oxidative stress damage, inflammation, and apoptosis. However, the potential mechanism of how Sesn2 regulates mitophagy and apoptosis in severe acute pancreatitis (SAP) remains unclear. In the study, RAW264.7 (macrophage cell Line) cellular inflammation model established by lipopolysaccharide (LPS) treatment as well as LPS and CAE-induced SAP mouse model (wild-type and Sen2 Knockout mouse) were used. Our study showed that LPS stimulation significantly increased the level of Sesn2 in RAW264.7 cells, Sesn2 increased mitochondrial membrane potential, decreased inflammation levels, mitochondrial superoxide levels and apoptosis, and also promoted monocyte macrophages toward the M2 anti-inflammatory phenotype, suggesting a protective effect of Sesn2 on mitochondria. Further, Sesn2 increased mitophagy and decreased apoptosis via modulating the PINK1-Parkin signaling. Meanwhile, knockout of Sesn2 exacerbated pancreatic, mitochondrial damage and inflammation in a mouse model of SAP. In addition, the protective effect of Sesn2 against SAP was shown to be associated with mitophagy conducted by the PINK1-Parkin pathway via inhibiting apoptosis. These findings reveal that Sesn2 in balancing mitochondrial autophagy and apoptosis by modulating the PINK1-Parkin signaling may present a new therapeutic strategy for the treatment of SAP.

Neuroprotective effects of phytochemicals through autophagy modulation in ischemic stroke

Stroke is a serious life-threatening medical condition. Understanding the underlying molecular mechanisms of this condition is crucial to identifying novel therapeutic targets that can improve patient outcomes. Autophagy is an essential mechanism for the destruction of damaged intracellular components that maintains homeostasis in physiological or pathological conditions. This process is involved in the pathophysiology of stroke. Phytochemicals are bioactive naturally occurring compounds present in plants. This paper reviews the neuroprotective roles of phytochemicals in ischemic stroke through autophagy modulation. It summarizes the interactions of various phytochemicals with key molecular targets of the autophagy pathway in ischemic stroke, including PI3K/Akt/mTOR, Beclin-1, and AMPK. Due to the ability of various phytochemicals to alter autophagic flux, they may provide promising opportunities in the development of new treatments and the improvement of stroke management.

Advancements in the Research of Astragalus membranaceus for the Treatment of Colorectal Cancer

Colorectal cancer, characterized by its high incidence, concealed early symptoms, and poor prognosis at advanced stages, ranks as the third leading cause of cancer-related deaths worldwide. Astragalus membranaceus (AM) refers to the dried roots of Astragalus membranaceus (Fisch.) Bge. var. mongholicus (Bge.) Hsiao and Astragalus membranaceus (Fisch.) Bge. In the theory of Traditional Chinese Medicine (TCM), it is believed to have the functions of tonifying qi and lifting yang, as well as generating body fluids and nourishing blood. It can effectively treat cancer caused by the deficiency of vital energy and susceptibility to external diseases. Modern research has confirmed that the active components of AM, including Astragalus polysaccharides, flavonoids (formononetin and calycosin), Astragalus saponins (Astragaloside I and Astragaloside III), and Astragalus nanovesicles, are effective in the treatment of colorectal cancer. The mechanisms mainly involve inducing apoptosis, inhibiting tumor angiogenesis and the metastasis of cancer cells, regulating the cell cycle and tumor microenvironment, and reversing drug resistance. Moreover, it offers a synergistic enhancement when used in combination with chemotherapy, radiotherapy, targeted therapy, or surgical treatment. AM also has great potential in treating colorectal cancer when combined with other herbs. This review summarizes the relevant research findings on the treatment of colorectal cancer with AM, as well as its main pharmacological effects and molecular mechanisms, aiming to provide guidance for the development of new drugs, and offer direction for the conduct of more related research and promoting the development and application of AM.

Sestrin2 remedies neuroinflammatory response by inhibiting A1 astrocyte conversion via autophagy

Most central nervous diseases are accompanied by astrocyte activation. Autophagy, an important pathway for cells to protect themselves and maintain homeostasis, is widely involved in regulation of astrocyte activation. Reactive astrocytes may play a protective or harmful role in different diseases due to different phenotypes of astrocytes. It is an urgent task to clarify the formation mechanisms of inflammatory astrocyte phenotype, A1 astrocytes. Sestrin2 is a highly conserved protein that can be induced under a variety of stress conditions as a potential protective role in oxidative damage process. However, whether Sestrin2 can affect autophagy and involve in A1 astrocyte conversion is still uncovered. In this study, we reported that Sestrin2 and autophagy were significantly induced in mouse hippocampus after multiple intraperitoneal injections of lipopolysaccharide, with the elevation of A1 astrocyte conversion and inflammatory mediators. Knockdown Sestrin2 in C8-D1A astrocytes promoted the levels of A1 astrocyte marker C3 mRNA and inflammatory factors, which was rescued by autophagy inducer rapamycin. Overexpression of Sestrin2 in C8-D1A astrocytes attenuated A1 astrocyte conversion and reduced inflammatory factor levels via abundant autophagy. Moreover, Sestrin2 overexpression improved mitochondrial structure and morphology. These results suggest that Sestrin2 can suppress neuroinflammation by inhibiting A1 astrocyte conversion via autophagy, which is a potential drug target for treating neuroinflammation.

Calycosin inhibits the proliferation and metastasis of renal cell carcinoma through the MAZ/HAS2 signaling pathway

Calycosin (Caly), a flavonoid compound, demonstrates a variety of beneficial properties. However, the specific mechanisms behind Caly's anticancer effects remain largely unexplored. Network pharmacology was used to explore the potential targets of Caly in renal cancer. Additionally, RNA-seq sequencing was used to detect changes in genes in renal cancer cells after Caly treatment. Validation was carried out through quantitative reverse transcription-PCR and Western blot analysis. The luciferase reporter assay was applied to pinpoint the interaction site between MAZ and HAS2. Furthermore, the immunoprecipitation assay was utilized to examine the ubiquitination and degradation of MAZ. In vivo experiments using cell line-derived xenograft mouse models were performed to assess Calycosin's impact on cancer growth. Network pharmacology research suggests Caly plays a role in promoting apoptosis and inhibiting cell adhesion in renal cancer. In vitro, Caly has been observed to suppress proliferation, colony formation, and metastasis of renal cancer cells while also triggering apoptosis. Additionally, it appears to diminish hyaluronic acid synthesis by downregulating HAS2 expression. MAZ is identified as a transcriptional regulator of HAS2 expression. Calycosin further facilitates the degradation of MAZ via the ubiquitin-proteasome pathway. Notably, Caly demonstrates efficacy in reducing the growth of renal cell carcinoma xenograft tumors in vivo. Our findings indicate that Caly suppresses the proliferation, metastasis, and progression of renal cell carcinoma through its action on the MAZ/HAS2 signaling pathway. Thus, Caly represents a promising therapeutic candidate for the treatment of renal cell carcinoma.

Calycosin Enhances Heat Shock Related-Proteins in H9c2 Cells to Modulate Survival and Apoptosis against Heat Shock

Heat shock proteins (HSPs), which function as chaperones, are activated in response to various environmental stressors. In addition to their role in diverse aspects of protein production, HSPs protect against harmful protein-related stressors. Calycosin exhibits numerous beneficial properties. This study aims to explore the protective effects of calycosin in the heart under heat shock and determine its underlying mechanism. H9c2 cells, western blot, TUNEL staining, flow cytometry, and immunofluorescence staining were used. The time-dependent effects of heat shock analyzed using western blot revealed increased HSP expression for up to 2[Formula: see text]h, followed by protein degradation after 4[Formula: see text]h. Hence, a heat shock damage duration of 4[Formula: see text]h was chosen for subsequent investigations. Calycosin administered post-heat shock demonstrated dose-dependent recovery of cell viability. Under heat shock conditions, calycosin prevented the apoptosis of H9c2 cells by upregulating HSPs, suppressing p-JNK, enhancing Bcl-2 activation, and inhibiting cleaved caspase 3. Calycosin also inhibited Fas/FasL expression and activated cell survival markers (p-PI3K, p-ERK, p-Akt), indicating their cytoprotective properties through PI3K/Akt activation and JNK inhibition. TUNEL staining and flow cytometry confirmed that calycosin reduced apoptosis. Moreover, calycosin reversed the inhibitory effects of quercetin on HSF1 and Hsp70 expression, illustrating its role in enhancing Hsp70 expression through HSF1 activation during heat shock. Immunofluorescence staining demonstrated HSF1 translocation to the nucleus following calycosin treatment, emphasizing its cytoprotective effects. In conclusion, calycosin exhibits pronounced protective effects against heat shock-induced damages by modulating HSP expression and regulating key signaling pathways to promote cell survival in H9c2 cells.

Allicin regulates Sestrin2 ubiquitination to affect macrophage autophagy and senescence, thus inhibiting the growth of hepatoma cells

BACKGROUND

Allicin regulates macrophage autophagy and senescence, and inhibits hepatoma cell growth. This study investigated the mechanism by which allicin inhibits the growth of hepatoma cells.

METHODS

Hepa1-6 mouse hepatoma cells were subcutaneously injected into C57BL/6 J mice to construct a tumor transplantation model. Macrophages were cultured with the supernatant of hepatoma cells to construct a cell model. The levels of mRNA and proteins and the level of Sestrin2 ubiquitination were measured by RTqPCR, immunofluorescence and Western blotting. The levels of autophagy-related factors and the activity of senescence-associated β-galactosidase were determined by kits, and protein stability was detected by cycloheximide (CHX) tracking.

RESULTS

Data analysis of clinical samples revealed that RBX1 was highly expressed in tumor tissues, while Sestrin2 was expressed at low levels in tumor tissues. Allicin can promote the expression of the autophagy-related proteins LC3 and Beclin-1 in tumor macrophages and inhibit the expression of the aging-related proteins p16 and p21, thus promoting autophagy in macrophages and inhibiting cell senescence. Moreover, allicin can inhibit the expression of RBX1, thereby reducing the ubiquitination of Sestrin2, enhancing the stability of Sestrin2, activating autophagy in tumor macrophages and inhibiting senescence. In addition, allicin treatment inhibited the proliferation and migration of hepatoma carcinoma cells cocultured with macrophages and significantly improved the development of liver cancer in mice.

CONCLUSION

Allicin can affect the autophagy of macrophages and restrain the growth of hepatoma cells by regulating the ubiquitination of Sestrin2.

Exploring the multi-targeting phytoestrogen potential of Calycosin for cancer treatment: A review

Cancer remains a significant challenge in the field of oncology, with the search for novel and effective treatments ongoing. Calycosin (CA), a phytoestrogen derived from traditional Chinese medicine, has garnered attention as a promising candidate. With its high targeting and low toxicity profile, CA has demonstrated medicinal potential across various diseases, including cancers, inflammation, and cardiovascular disease. Studies have revealed that CA possesses inhibitory effects against a diverse array of cancers. The underlying mechanism of action involves a reduction in tumor cell proliferation, induction of tumor cell apoptosis, and suppression of tumor cell migration and invasion. Furthermore, CA has been shown to enhance the efficacy of certain chemotherapeutic drugs, making it a potential component in treating malignant tumors. Given its high efficacy, low toxicity, and multi-targeting characteristics, CA holds considerable promise as a therapeutic agent for cancer treatment. The objective of this review is to present a synthesis of the current understanding of the antitumor mechanism of CA and its research progress.

Circular RNAs: characteristics, functions, mechanisms, and potential applications in thyroid cancer

Thyroid cancer (TC) is one of the most common endocrine malignancies, and its incidence has increased globally. Despite extensive research, the underlying molecular mechanisms of TC remain partially understood, warranting continued exploration of molecular markers for diagnostic and prognostic applications. Circular RNAs (circRNAs) have recently garnered significant attention owing to their distinct roles in cancers. This review article introduced the classification and biological functions of circRNAs and summarized their potential as diagnostic and prognostic markers in TC. Further, the interplay of circRNAs with PI3K/Akt/mTOR, Wnt/β-catenin, MAPK/ERK, Notch, JAK/STAT, and AMPK pathways is elaborated upon. The article culminates with an examination of circRNA's role in drug resistance of TC and highlights the challenges in circRNA research in TC.

Sestrin2 ameliorates diabetic retinopathy by regulating autophagy and ferroptosis

Diabetic retinopathy (DR) is a serious microvascular complication of diabetes. The aim of this study was to explore the effect of Sestrin2 on DR through the regulation of autophagy and ferroptosis levels and its mechanism. In vitro and in vivo DR models were established by high glucose (HG) and streptozotocin (STZ) induction of ARPE-19 human retinal pigment epithelial cells and C57BL/6 mice, respectively. In this study, we demonstrated that after HG treatment, the activity of ARPE-19 cells was decreased, the apoptosis rate was increased, endoplasmic reticulum (ER) stress was activated, autophagy levels were decreased, and ferroptosis levels were increased. Overexpression of Sestrin2 enhanced cell viability, reduced apoptosis and ferroptosis, and enhanced autophagy. However, the effect of overexpression of Sestrin2 was attenuated after the addition of the STAT3 phosphorylation activator Colivelin TFA (C-TFA), the mTOR pathway activator MHY1485 or the autophagy inhibitor 3-methyladenine (3-MA). In addition, the effect of Sestrin2 knockdown on cells was opposite to the effect of overexpression of Sestrin2, while the effect of Sestrin2 knockdown was attenuated after treatment with the ER stress inhibitor 4-phenylbutyric acid (4-PBA). Animal experiments also confirmed the results of cell experiments and attenuated the effects of overexpression of Sestrin2 after injection of the ferroptosis activators erastin or 3-MA. Our study revealed that Sestrin2 inhibits ferroptosis by inhibiting STAT3 phosphorylation and ER stress and promoting autophagy levels, thereby alleviating DR.

Adiponectin Inhibits the Progression of Obesity-Associated Papillary Thyroid Carcinoma Through Autophagy

CONTEXT

Obesity is a risk factor for the development of papillary thyroid cancer (PTC). However, the molecular mechanisms by which obesity promotes PTC are unclear.

OBJECTIVE

This study aims to identify adipokines that are linked to PTC progression.

METHODS

An adipokine antibody array was used to determine the serum levels of 40 adipokines in normal-weight and obese PTC patients. Enzyme-linked immunosorbent assay was used to determine the serum levels of adiponectin. Recombinant human adiponectin was produced by human adipose-derived stem cells and used to treat PTC cells. Cell proliferation and migration were evaluated using the CCK8 and Transwell assays. Bioinformatics analysis was used to predict mechanisms by which adiponectin affects PTC.

RESULTS

Adipokines differentially expressed between normal-weight and obese patients showed a gender-dependent pattern. Obese PTC patients had a significantly lower serum adiponectin level than normal-weight patients, especially in female individuals. Adiponectin levels were negatively correlated with aggressive features of PTC, including tumor diameter > 1 cm, extrathyroidal extension, and lymph node metastasis. Recombinant human adiponectin inhibited the proliferation and migration of human PTC cells in vitro. Bioinformatics analysis identified adiponectin receptor 2 (ADIPOR2) and the autophagy pathway as possible mediators of adiponectin function in TC. In vitro experiments confirmed that adiponectin activated autophagy in PTC cells. These findings shed new lights into the role and mechanisms of adiponectin in TC pathogenesis.

CONCLUSION

Adiponectin is involved in development of obesity-related PTC. Adiponectin can directly inhibit thyroid cancer growth and metastasis through the autophagy pathway.

Liraglutide improves sevoflurane-induced postoperative cognitive dysfunction via activating autophagy and inhibiting apoptosis

BACKGROUND

Postoperative cognitive dysfunction (POCD) is a common postoperative complication in elderly patients. Liraglutide (LRG) has high homology (97%) with natural glucagon like peptide-1, and it has been proved to be effective in some nervous system diseases. Whether LRG could regulate POCD has not been reported.

METHODS

Sevoflurane (Sev) was used to simulate postoperative cognitive dysfunction (POCD) model. Morris water maze test was performed to evaluate the memory ability and neurological function of rats. Escape latency, swim distance, crossing platform times, average velocity, and targeting quadrant time were analyzed. The cell apoptosis, mRNA and protein expression were measured through flow cytometry, PCR, and western blotting, respectively.

RESULTS

LRG significantly improved the memory ability and neurological function of Sev-treated rats, but 3-MA reversed the effects of LRG. LRG remarkably inhibited apoptosis but up-regulated autophagy related proteins both in vivo and in vitro levels. However, knocking down AMPK could markedly reverse the influence of LRG on apoptosis, autophagy, and cell apoptosis.

CONCLUSIONS

LRG induced autophagy activation can maintain cell homeostasis and promote cell survival by blocking the apoptotic pathway. LRG could improve Sev-induced POCD via activating autophagy, inhibiting apoptosis, and regulating AMPK/mTOR signaling pathway. This study provides a novel therapeutic strategy for the prevention and treatment of POCD.

Eupatilin inhibits pulmonary fibrosis by activating Sestrin2/PI3K/Akt/mTOR dependent autophagy pathway

BACKGROUND

Idiopathic pulmonary fibrosis (IPF) is a progressive chronic inflammatory disease with poor clinical outcomes and ineffective drug treatment options. Eupatilin is a major component extracted from the traditional herbal medicine Artemisia asiatica Nakai. Notably, it was demonstrated to have an anti-fibrosis effect in endometrial fibrosis, vocal fold, and hepatic fibrosis. Its role and mechanism in IPF remain unclear.

METHODS

This study used the TGF-β1-induced human embryonic lung fibroblasts (MRC-5) activation, IPF lung fibroblasts, and bleomycin-induced lung fibrosis mice model. Western blot, immunofluorescence staining, quantitative real time-PCR, hematoxylin and eosin staining, Masson's trichrome staining, and immunohistochemistry were used to evaluate the effects of eupatilin on fibroblast activation, pulmonary fibrosis, and autophagy. The autophagosomes were observed with a transmission electron microscope (TEM). RNA sequencing was used to determine the signaling pathway and key regulator related to autophagy.

RESULTS

Eupatilin significantly decreased the expression of Col1A1, fibronectin, α-SMA, and SQSTM1/p62. In contrast, it increased the expression of LC3B II/I and the number of autophagosomes in TGF-β1 treated MRC-5, IPF lung fibroblasts, and bleomycin-induced lung fibrosis mice model; it also alleviated bleomycin-induced lung fibrosis. The KEGG pathway mapping displayed that PI3K/Akt and Sestrin2 were associated with the enhanced fibrogenic process. Eupatilin suppressed the phosphorylation of PI3K/Akt/mTOR. Autophagy inhibitor 3-methyladenine (3-MA) and Akt activator SC-79 abrogated the anti-fibrotic effect of eupatilin. Sestrin2 expression was also downregulated in TGF-β1 treated lung fibroblasts and lung tissues of the bleomycin-induced pulmonary fibrosis mice model. Furthermore, eupatilin promoted Sestrin2 expression, and the knockdown of Sestrin2 significantly aggravated the degree of fibrosis, increased the phosphorylation of PI3K/Akt/mTOR, and decreased autophagy.

CONCLUSION

These findings indicate that eupatilin ameliorates pulmonary fibrosis through Sestrin2/PI3K/Akt/mTOR-dependent autophagy pathway.

Sestrin2 in diabetes and diabetic complications

Diabetes is a global health problem which is accompanied with multi-systemic complications. It is of great significance to elucidate the pathogenesis and to identify novel therapies of diabetes and diabetic complications. Sestrin2, a stress-inducible protein, is primarily involved in cellular responses to various stresses. It plays critical roles in regulating a series of cellular events, such as oxidative stress, mitochondrial function and endoplasmic reticulum stress. Researches investigating the correlations between Sestrin2, diabetes and diabetic complications are increasing in recent years. This review incorporates recent findings, demonstrates the diverse functions and regulating mechanisms of Sestrin2, and discusses the potential roles of Sestrin2 in the pathogenesis of diabetes and diabetic complications, hoping to highlight a promising therapeutic direction.

Arsenic induced autophagy-dependent apoptosis in hippocampal neurons via AMPK/mTOR signaling pathway

Arsenic contamination of groundwater remains a serious public health problem worldwide. Arsenic-induced neurotoxicity receives increasing attention, however, the mechanism remains unclear. Hippocampal neuronal death is regarded as the main event of arsenic-induced cognitive dysfunction. Mitochondria lesion is closely related to cell death, however, the effects of arsenic on PGAM5-regulated mitochondrial dynamics has not been documented. Crosstalk between autophagy and apoptosis is complicated and autophagy has a dual role in the apoptosis pathways in neuronal cells. In this study, arsenic exposure resulted in mitochondrial PGAM5 activation and subsequent activation of apoptosis and AMPK-mTOR dependent autophagy. Intervention by autophagy activator Rapamycin or inhibitor 3-MA, both targeting at mTOR, accordingly induced activation or inhibition of apoptosis. Intervention by MK-3903 or dorsomorphin, activator or inhibitor of AMPK, received similar results. Our findings suggested that arsenic-induced PGAM5 activation played a role in AMPK-mTOR dependent autophagy and arsenic induced autophagy-dependent apoptosis in hippocampal neurons via AMPK/mTOR signaling pathway.

Calycosin Alleviates Lupus Nephritis by Activating the Nrf2/HO-1 Signaling Pathway

Lupus nephritis is a serious condition, for which treatments are limited; hence, there is a need for new cure approaches. The aim of this study was to evaluate the therapeutic effects of calycosin against lupus nephritis induced by lipopolysaccharide (LPS) in human renal cortex proximal convoluted tubule epithelial cells (HK-2). HK-2 cells were stimulated with 1 μg/ml LPS to create a lupus nephritis cell model; the cells were pretreated with calycosin. Cell viability and apoptosis rate were determined using the cell counting kit-8 assay and flow cytometry, respectively. A caspase-3 activity detection kit was used to determine caspase-3 activity. Interleukin (IL)-6, IL-1β, and tumor necrosis factor alpha (TNF-α) levels were determined using enzyme-linked immunosorbent assay kits. Lactate dehydrogenase (LDH) level was determined using an LDH assay kit. Finally, western blotting and reverse transcription-quantitative polymerase chain reaction were performed to determine apoptosis-related protein levels and nuclear factor erythroid 2–related factor 2 (Nrf2)/heme oxygenase-1 (HO-1) signaling. Calycosin had no cytotoxic effects on HK-2 cells. Lipopolysaccharide stimulation significantly inhibited cell viability; increased the IL-6, IL-1β, and TNF-α levels; and elevated apoptosis rate, caspase3 activity, and LDH level in HK-2 cells. The protein level of cleaved caspase3 was also increased in LPS-treated HK-2 cells. In addition, the pattern of Nrf2/HO-1 signaling was disturbed by LPS. These effects were reversed by calycosin treatment. Calycosin could alleviate LPS-induced lupus nephritis and may thus be a novel agent for its treatment.

Graphical Abstract